spdif or usb?

 You are talking about USB Audio Class 2 standard which allows 24 and 32 bit. Microsoft windows does not even support that yet and the last I heard and you would need a third party driver for it. Win7 may have a better chance with drivers to support that standard. CD's are still 16 bit 44K and much new music today is compressed anyway. MP3 recording are still very popular and SACD  DVD-Audio never took off in a big way. My best DAC can do 24bit 96k which is perfectly fine for me today and the future. I have even heard that using 24bit 196k rate may tax the whole system and can degrade music quality.

Unless you have a special need for it 32 bit is just useless for music at this point.

What I do fine interesting is that USB3 can make it easier to transfer and record 60 channels using 24 bits at 96 kHz, for example. I just do not have that need in a home at this time. I do not believe in chasing after equipment that has higher numbers unless it will improve sound quality. It is like a “solution” in search of a “problem”. My equipment today will still be state of the art in the future as far music quality goes. My main issue today is to find more 24bit 96k recordings by my favorite artists and groups as possible. I still enjoy my huge CD’s collection as well.    

 whichwhich allow

My computer does not  have S/PDIF out so my chain looks like this: USB to X-FI HD to 24/96 Toslink S/PDIF DVD designated input at rear of Sony TA-E9000ES pre/pro. Although the pre/ro is 12 years old, the sound processed by it, coming  from my  iTunes library, is simply dazzling. The noise floor is utterly silent. And, my experiments comparing materials on CD, SACD, BD, and vinyl with content from the iTunes library suggests the 256k material from the iTunes library is indistinguishable from the direct sources.  I'm so satisfied with the listening experience, my days of upgrading are over for good. Thing is, I saw an example of my Sony TA-E9000ES the other day on ebay for about $70.00. It made me think, someone looking for state-of-the-art audio could, with a little research, build a nice system with vintage components off ebay for peanuts.